Tach Trouble. Its bouncing all over the place

[Full Throttle]

So i just got home from Vacation and i took the bike out for a nice ride. Well i noticed that the Needle is bouncing all over the place. I was not really worried about it affecting the bike but im wondering if there is an electrical problem or if the sensor is messed up and if i need to replace it. It ran fine prior to my vacation but i did just have it taken all apart and cleaned it really good so i guess its possible that i could of loosened some wires up. What do yall think?